working with mahogany crotch veneer
#21
  Re: RE: working with mahogany crotch veneer by mr_skittle (First of all Dave, t...)
(11-05-2021, 07:47 PM)mr_skittle Wrote: There are just a little over 12 x 12. My concern with using plywood is that it will be too thick by the time I get the veneer on, especially if I need to use 2 or 3 layers of veneer. Is there plywood thinner than 1/4 inch that is meant for veneering?

As far as glue goes, I have ordered some Ultra-cat PPR from veneersupplies.com, which is urea-formaldehyde. As far as I understand this is the only type of glue to use on crotch veneer, or at least mahogany crotch.

My understanding at this point is that I should put a layer of veneer on both sides of the panel. That shouldn't be a problem as the batch I got came with 5 sheets. One question I have is if I am supposed to also put a layer of veneer between the mahogany and the panel. I do have some paper-backed, curly maple veneer that I could use if it's necessary.
There is no special ply for veneering, I don't go thinner than 3/8. 1/4", you're going to have to anticipate issues with it staying flat, even with a balance veneer.

I'm not aware of any specific glue for crotch veneer, other than one that dries hard. I used hide glue on my table.

The only resin glue I've worked with is weldwood. If this is anything like it, it is a mess to use and if you do get any bleed through, it will be an bear to get off, and risky for thin veneer. I thought resin glue was more for vacuum pressing.
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#22
  Re: working with mahogany crotch veneer by mr_skittle (I've gotten in a lit...)
The brand I used was PL FIX. I'm not sure that brand is still available but the DAP "Plastic Wood" appears similar.

If I were the one making these panels here is how I would proceed. First, inspect the sheets of veneer for defects including cracks and tear-out. Hold the sheet up to a bright light source to locate any cracks. Any cracks will need to be sealed with veneer tape(the tape stays on until the glue up is complete) on the show face. If no light can be seen, proceed to glue-up but if light can be seen through the pores then seal the glue side with the wood filler. After the filler is dry and sanded, blue-tape the veneer to the wet glue side of the panel then put the panel into the press and press. Then rinse and repeat on the back.

I recommend that you play around with the filler on scrap to get an idea how to apply and spread. Practice until you get a consistent coat that only fills the pores, the sanding removes the rest. I use a credit card to spread the filler. Maintaining the consistency of the filler can be difficult. I use a small container then put in a thumb sized chunk of filler then pour a small amount of acetone and stir until it becomes similar to light cream, add acetone to maintain as the filler dries quickly.

The entire process is easy after a little practice.
When you don’t get what you want, you get experience!
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#23
  Re: working with mahogany crotch veneer by mr_skittle (I've gotten in a lit...)
Appearlenty I decided to chose the most finicky type of veneer possible. Between the flattening, pore filling, special glue, and vacuum bag I'm really in up to my neck. Oh well, guess its a pretty modest investment for the supplies and experience. Veneering is one of those value-adding skills that will serve me well as a professional furniture maker in the future.

I ordered some resin glue from veneersupplies.com. I got a pound of the ULTRA-cat PPR. The price was modest but shipping these days... It was more for shipping than the product cost. I also found this Famo-Wood filler on Amazon. Looks to be the same kind of stuff. I'm just going to pick up some Wood Plastic putty today at Home Depot. Its the second time in a week that my first choice, Menards, didn't have what I needed. The shelves in their finish/paint dept keep getting more bare.

Let me ask for one clarification on applying the filler. I don't want the filler to bleed through, right? I'm not trying to 'fill' the pores and much as I am trying to clog them from the glue side.

As an aside, I'm curious if there is a reason for using solvent-based filler instead of water-based?
How do you know you're learning anything if you don't screw up once in awhile?

My blog: http://birdsandboards.blogspot.com/
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#24
  Re: RE: working with mahogany crotch veneer by mr_skittle (Appearlenty I decide...)
(11-09-2021, 08:59 AM)mr_skittle Wrote: Appearlenty I decided to chose the most finicky type of veneer possible. Between the flattening, pore filling, special glue, and vacuum bag I'm really in up to my neck. Oh well, guess its a pretty modest investment for the supplies and experience. Veneering is one of those value-adding skills that will serve me well as a professional furniture maker in the future.

I ordered some resin glue from veneersupplies.com. I got a pound of the ULTRA-cat PPR. The price was modest but shipping these days... It was more for shipping than the product cost. I also found this Famo-Wood filler on Amazon. Looks to be the same kind of stuff. I'm just going to pick up some Wood Plastic putty today at Home Depot. Its the second time in a week that my first choice, Menards, didn't have what I needed. The shelves in their finish/paint dept keep getting more bare.

Let me ask for one clarification on applying the filler. I don't want the filler to bleed through, right? I'm not trying to 'fill' the pores and much as I am trying to clog them from the glue side.
Can you post some pics of the veneer? I've never seen anyone fill prior to gluing, is that something you've seen somewhere?

My (limited) experience with crotch & burl, I found the fissures or cracks would close up pretty good after softening, but when the glue dried, they pulled back open. You won't know until the glue is dried.

Even though I've never used resin glue other than laminations, from the sound of it, I really think you should consider using use hide glue (Old Brown Glue can be vac pressed). Bleed through residue is easily removed and and hide glue doesn't interfere with finish. Then use a grain filler prior to finishing.
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#25
  Re: RE: working with mahogany crotch veneer by mr_skittle (Appearlenty I decide...)
(11-09-2021, 08:59 AM)mr_skittle Wrote: Appearlenty I decided to chose the most finicky type of veneer possible. Between the flattening, pore filling, special glue, and vacuum bag I'm really in up to my neck. Oh well, guess its a pretty modest investment for the supplies and experience. Veneering is one of those value-adding skills that will serve me well as a professional furniture maker in the future.

I ordered some resin glue from veneersupplies.com. I got a pound of the ULTRA-cat PPR. The price was modest but shipping these days... It was more for shipping than the product cost. I also found this Famo-Wood filler on Amazon. Looks to be the same kind of stuff. I'm just going to pick up some Wood Plastic putty today at Home Depot. Its the second time in a week that my first choice, Menards, didn't have what I needed. The shelves in their finish/paint dept keep getting more bare.

Let me ask for one clarification on applying the filler. I don't want the filler to bleed through, right? I'm not trying to 'fill' the pores and much as I am trying to clog them from the glue side.

As an aside, I'm curious if there is a reason for using solvent-based filler instead of water-based?

Your choice of veneer for this project is high on the pucker chart. Regardless of how your panels turn out, the experience will be a learning exercise(note my sig-line). The truth is that veneer can turn a simple, plain project into something special.

With the projects I've done, I have come to the conclusion that when working with difficult veneer, the most important thing is, once the veneer has been made flat and dry I do everything I can to not introduce moisture(water). With some veneers a small amount of moisture has no effect but with others a tiny increase in humidity can have a major impact. The problem may appear only after the panel has been finished. The solvent based filler does two things, first it "clogs the pores" and forms a barrier to any moisture from the glue. With a difficult veneer I will also pad a 1.5 pound cut of shellac to the face when I pull the panel out of the press.    

Did you try viewing the veneer with light?
When you don’t get what you want, you get experience!
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#26
  Re: RE: working with mahogany crotch veneer by rwe2156 ([quote="mr_skittle" ...)
(11-09-2021, 09:51 AM)rwe2156 Wrote: Can you post some pics of the veneer?  I've never seen anyone fill prior to gluing, is that something you've seen somewhere?

My (limited) experience with crotch & burl, I found the fissures or cracks would close up pretty good after softening, but when the glue dried, they pulled back open. You won't know until the glue is dried.

Even though I've never used resin glue other than laminations, from the sound of it, I really think you should consider using use hide glue (Old Brown Glue can be vac pressed).  Bleed through residue is easily removed and and hide glue doesn't interfere with finish.  Then use a grain filler prior to finishing.

Using thinned putty to "plug" the pores is recommended by Dave, the other person contributing to this thread. It struck me as overkill at first but then I held the veneer up to the light and saw all the end grain pores. I'm seriously concerned about bleed-through and a quick treatment to clog those pores makes sense to me. 

I appreciate your recommendation of hide glue, and it might well work fine, but I'm putting my faith in modern glue developments going with the urea resin that I got from veneer supplies. My understanding of crotch veneer is that the very stable and hard cured resin glue is best choice. If veneering becomes part of my regular work, be sure I'll be trying other approaches. 


   

   
How do you know you're learning anything if you don't screw up once in awhile?

My blog: http://birdsandboards.blogspot.com/
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#27
  Re: RE: working with mahogany crotch veneer by Dave Crow ([quote="mr_skittle" ...)
(11-09-2021, 01:49 PM)Dave Crow Wrote: Your choice of veneer for this project is high on the pucker chart. Regardless of how your panels turn out, the experience will be a learning exercise(note my sig-line). The truth is that veneer can turn a simple, plain project into something special.

With the projects I've done, I have come to the conclusion that when working with difficult veneer, the most important thing is, once the veneer has been made flat and dry I do everything I can to not introduce moisture(water). With some veneers a small amount of moisture has no effect but with others a tiny increase in humidity can have a major impact. The problem may appear only after the panel has been finished. The solvent based filler does two things, first it "clogs the pores" and forms a barrier to any moisture from the glue. With a difficult veneer I will also pad a 1.5 pound cut of shellac to the face when I pull the panel out of the press.    

Did you try viewing the veneer with light?

The veneer choice was a bit of an impulse decision. I had a book-matched panel ready to go but I realized that after thicknessing it, the grain pattern didn't really mirror anymore. After a late night in the shop I was just staring at the dresser and it hit me, crotch veneer for the doors. I worked in a turn-of-the-century mansion as a tour guide for a summer and I'll never forget the mahogany crotch around the fireplace in the sitting room. Floor to ceiling, 10+ feet of incredible crotch-wood. The kind of thing that's either extinct or unavailable these days. 

I did look through the veneer in front of a bright light. It's holey. I can definitely see how a little filler from behind is a viable idea. All the red is end grain and the brown is 'regular' grain. Over half of what I planning on using for the panel is end grain. 

   
How do you know you're learning anything if you don't screw up once in awhile?

My blog: http://birdsandboards.blogspot.com/
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#28
  Re: working with mahogany crotch veneer by mr_skittle (I've gotten in a lit...)
That veneer is almost identical to what I used. The figured center part is where the cracks were wider after the glue dried. Maybe that's more a hide glue thing, I don't know.

Try the filler but don't expect it to work well. Let us know how the resin glue works out.
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#29
  Re: working with mahogany crotch veneer by mr_skittle (I've gotten in a lit...)
I'm hoping to get the work done in the next couple of days. I'll be sure to post pictures and report on the process and results.
How do you know you're learning anything if you don't screw up once in awhile?

My blog: http://birdsandboards.blogspot.com/
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#30
  Re: working with mahogany crotch veneer by mr_skittle (I've gotten in a lit...)
I did a test run last night with some scraps from the edges of the veneer sheets. It was an enlightening experience and I'm very happy I was able to do it. My few takeaways are as follows:

1. I'm not going to use the wood filler. On my test, I did both sides of a plywood scrap. I applied the filler to one and none to the other and I couldn't tell a difference once it came out of the press. I had no issues with bleeding through.

2. My mix of glue was the tiniest bit too thick, I think. It's really sensitive to water additions so I should be able to add it a few drops at a time and get it just right.

3. The platens need to be very close to the size of the workpiece. I made a set that is the maximum size that the bag will accommodate. I will need to cut them down to a more appropriate size.
How do you know you're learning anything if you don't screw up once in awhile?

My blog: http://birdsandboards.blogspot.com/
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